Traction devices are employed on vehicles driven over adverse riding surfaces, such as snow, ice, or mud. Traction devices include a penetrating surface which penetrates the riding surface to improve traction of the vehicle.
Prior traction devices include the conical bit and the wedge bit shown in FIGS. 2 and 3. Referring to FIGS. 2A and 2B, the conical bit is a solid cone having a circular cross section transverse to the direction of penetration, wherein the tip of the cone is used to penetrate the riding surface. While the conical bit is an aggressive device, providing deep penetration into the riding surface, the deep penetration results in accelerated wear and low durability of the bit.
Referring to FIGS. 3A and 3B, the wedge bit is formed of a slab of material wherein one corner of the slab is oriented to penetrate the riding surface. The penetrating surface of the wedge includes four facets, wherein two facets are parallel and two facets converge, thereby defining five edges. As the wedge does not penetrate as deeply as the conical bit, the wedge provides a more durable bit which does not provide the same degree of traction as the conical bit.
In an effort to obtain the benefits of the aggressive conical bit and the durable wedge bit, both bits are often arranged in predetermined patterns on the snowmobile track.
To improve durability, the bits of the prior art are often formed of carbide. However, as carbide is expensive to manufacture, machine, and attach to a less expensive steel mount, it is advantageous to minimize the amount of carbide.